Blue Earth County, Minnesota requires a county construction permit outside city limits for building, moving, adding onto or structurally altering a structure, except in Lime and Mankato Townships1. Those townships use the City of Mankato for building permits, while Blue Earth County administers septic permitting countywide2,3. County zoning applies in unincorporated areas except Lime and Mankato Townships4.
Do you need a building permit in Blue Earth County, Minnesota?
Blue Earth County requires a county construction permit outside city limits for building, moving, adding onto or structurally altering a structure; routine re-shingling, re-siding and replacement of windows or doors do not require that county permit.
Blue Earth County requires a county construction permit outside city limits for building, moving, adding onto or structurally altering a structure; routine re-shingling, re-siding and replacement of windows or doors do not require that county permit1. The county process does not apply in Lime Township, Mankato Township or cities1. Lime and Mankato Townships get building permits from the City of Mankato2. Inside Mankato city, the city issues mechanical and plumbing permits, with a minor-plumbing-repair exception9. North Mankato, which reaches into Blue Earth County but lies mainly in Nicollet County, issues its own building permits, subject to project exceptions10. Blue Earth County Property and Environmental Resources continues to administer septic permits countywide5. The Minnesota State Building Code governs covered work statewide, with conditional exceptions for agricultural buildings11. An eligible owner-builder may be exempt from residential-contractor licensing when occupying the property or retaining it as a rental, but the exemption does not waive permits or inspections and does not cover construction for resale or speculation6.
Who issues building permits in Blue Earth County, and how do you reach them?
For county-administered townships, call the Blue Earth County Property and Environmental Resources Department at (507) 304-4251.
For county-administered townships, call the Blue Earth County Property and Environmental Resources Department at (507) 304-42512. If the land is in Lime Township or Mankato Township, contact the City of Mankato at (507) 387-8600 instead2. Blue Earth County’s construction permit primarily addresses site setbacks; review can take up to 10 business days or longer and remains valid for one year1. Blue Earth County publishes construction-permit fees, but its construction page and fee schedule disagree on the current residential amount, so confirm the charge before applying12. Ask the applicable city, township or county office which building permits, plans and inspections your project requires; requirements vary by jurisdiction2. Under Minnesota’s occupancy rule, covered buildings cannot be used or occupied before the building official issues a certificate of occupancy; exceptions and temporary certificates may apply13.
Does Blue Earth County have zoning?
Blue Earth County’s Land Use Ordinance regulates unincorporated land; county administration excludes Lime and Mankato Townships.
Blue Earth County’s Land Use Ordinance regulates unincorporated land; county administration excludes Lime and Mankato Townships4,14. Lime and Mankato Townships have their own zoning ordinances, and Pleasant Mound Township regulates some uses alongside county zoning4. Mankato city sets its own zoning, while Blue Earth County Property and Environmental Resources handles septic permits countywide5,15. In county-zoned areas, the applicable district controls building height, lot coverage and impervious surface, but current numeric tables were not confirmed14. Road setbacks also depend on nearby development: construction cannot move closer to the road centerline than the existing structure on a developed parcel or adjacent structures beside vacant land without meeting the ordinance or obtaining a variance14. Residential lots subject to the county subdivision ordinance need at least one acre of usable buildable area, and a larger lot may be required for sewage treatment7. Call Planning & Zoning at (507) 304-4251 with the parcel number to identify the correct zoning authority and district16.
How do septic (SSTS) permits work in Blue Earth County?
Blue Earth County's Property and Environmental Resources Department administers septic environmental standards and permitting countywide.
Blue Earth County's Property and Environmental Resources Department administers septic environmental standards and permitting countywide5. Installing a septic system in Blue Earth County requires a county installation permit and an approved design from a licensed septic-system designer5. Before issuing the installation permit, the county requires soil verification, approved design documents, fee payment, an operating-permit application when applicable and a recorded easement agreement when applicable5. County staff inspect the system during installation and issue a certificate of compliance after it passes5. Only 2.7% of Blue Earth County soils are rated “not limited” for a conventional drain field, so do not assume a standard system will fit the parcel before soil verification17. For a new residential lot, identify at least two suitable private-septic locations before the building permit is issued7.
Can you live in an RV or tiny home on your land in Blue Earth County?
Blue Earth County allows county-regulated campgrounds in unincorporated areas to operate seasonally for no more than 7 months per year, with a county land-use development application.
Blue Earth County allows county-regulated campgrounds in unincorporated areas to operate seasonally for no more than 7 months per year, with a county land-use development application8. Campground RV wastewater must go to an approved municipal sewer where available or a compliant septic system, never onto the ground; campsites must be outside bluff impact zones and floodplain districts8. These campground standards do not establish permission to live in an RV on a private residential parcel8. We could not confirm residential RV occupancy, temporary camping, tiny-home occupancy or minimum dwelling size; ask the parcel’s zoning authority, starting with Blue Earth County Planning & Zoning for county-zoned land16. County zoning administration excludes Lime Township, Mankato Township and cities4.
Building a home in Blue Earth County, Minnesota: the steps, in order
Identify the building-permit authority: Blue Earth County serves most townships, while Lime and Mankato Townships use the City of Mankato.
- Identify the building-permit authority: Blue Earth County serves most townships, while Lime and Mankato Townships use the City of Mankato2.
- Identify the zoning authority and confirm the district, setbacks, height and lot-coverage rules4,14.
- For a land division in unincorporated Blue Earth County, confirm county subdivision approval requirements, buildable area, septic sites and access18.
- For a county-road driveway, call Public Works for field review and County Engineer approval before working in the right-of-way19.
- Have a licensed designer prepare the septic plan, complete county soil verification and obtain the installation permit5.
- Apply for the construction permit through the office with jurisdiction and confirm the fee and inspection schedule1,12.
- Arrange the septic installation inspection and confirm occupancy approval with the building official where the State Building Code is enforced5,13.
What to check before you buy land in Blue Earth County, Minnesota
Confirm the building-permit and zoning authorities before relying on a listing's claim that land is buildable.
Confirm the building-permit and zoning authorities before relying on a listing's claim that land is buildable2,4. A new residential lot needs at least 1 acre of usable buildable area and at least 2 suitable private-septic locations before a building permit is issued7. Under Blue Earth County subdivision rules, every lot must adjoin a public street, new lot lines must meet setbacks from existing buildings, and flag or panhandle access to new vacant lots is barred except for the agricultural-preservation exception for existing building sites7. A land split does not guarantee another county-road entrance; county right-of-way access needs review and County Engineer approval19. Check whether the site lies in a county floodway, flood fringe or general floodplain district; county rules may limit development, and a flood-fringe home generally needs fill that places its lowest floor, including the basement, above the 100-year flood level20. Minnesota generally requires well-construction notification and a filing fee; Blue Earth County’s local well requirements remain unconfirmed, so ask Property and Environmental Resources before drilling3,21.
Watch-outs
- Lime Township and Mankato Township are exceptions to Blue Earth County's building-permit and zoning administration: the City of Mankato issues their building permits, and the townships administer their own zoning2,4.
- Blue Earth County's construction page and published fee schedule list different residential construction-permit amounts, so confirm the current fee before applying12.
- A Blue Earth County property split does not guarantee a new county-road access, and working on a driveway or field entrance in the county right-of-way requires County Engineer approval19.
- Only 2.7% of Blue Earth County soils are rated “not limited” for a conventional septic drain field; the rating does not make septic impossible, but a site evaluation may point to an alternative system17.
- A flood-fringe home generally must sit on fill high enough that the lowest floor, including the basement, is above the 100-year flood level20.
Sources
21 official pages, each quoted and re-checked · written October 12, 2026
- Construction Permits
- Building Permit Information
- Septic Systems
- Planning & Zoning
- Septic System Installation Permits
- 2025 Minnesota Statutes, section 326B.805
- Blue Earth County Subdivision Ordinance
- Code of Ordinances: Chapter 24, Section 24-322, Campgrounds
- Mankato: Mankato Code § 5-118, Plumbing permit required (Blue Earth County)
- North Mankato: § 150.02 Building Permits (Blue Earth County)
- 2025 Minnesota Statutes, section 326B.121
- 2026 Fee Structure.xlsx
- Minnesota Rules part 1300.0220
- Table of Ordinances
- Mankato: Mankato Code § 10-95, Minimum lot area (Blue Earth County)
- Blue Earth County Planning & Zoning (blueearthcountymn.gov)
- Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
- blueearthcountymn.gov
- Building Permit Information
- Floodplain Management
- 2025 Minnesota Statutes, section 103I.205: Well Construction (Minnesota statewide rule)
Written October 12, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.
Off-grid gear
Going off-grid in Blue Earth County means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
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